Reasons for wanting higher mega pixel count

Started 4 months ago | Discussions
hjs_koeln Regular Member • Posts: 133
Re: Reasons for wanting higher mega pixel count
7

xh43k wrote:

JimKasson wrote:

KE_DP wrote:

Considering Moore's Law photography data in gigapixels are only a matter of time - maybe even terapixels.

There are some considerable difficulties building a lens that can provide terapixels of information -- as opposed to noise -- in a single capture. The simplest one is diffraction.

I do have tiny zeiss lenses in my eyes after cataract surgery (im 30yo) and they seem sharp.

Resolution of an eye according to quick google search seems to be 324 megapixels.

Considering the size of the lenses in my eyes I think it could be 'viable' - of course, with much higher price.

It is almost impossible to really equate what the human eye can (and cannot) see to a particular number of megapixels. Visual physiology is totally different than photography, as a huge amount of processing of incoming light happens in the retina before the resulting impulses hit the brain.

Each eye has approx. 100 million photoreceptor cells. Of those, there are approx. 94 million rods, and 5-6 million cones. Wikipedia says 120 mil : 6 mil, but the numbers I used can be found in the scientific literature too, so I´m not sure which ones are more accurate.

Each eye bundles the fibers from those photoreceptor cells into the optic nerve, but each optic nerve has only between 600.000 and 1.5 million fibers. Therefore, in the retina there´s a convergence on a scale  of 100:1 going on before individual fibers form the optic nerve.

This convergence happens in the retina over 3 tiers of neuronal cells in a vertical arrangement (with rods/cones being the 1° neurons, bipolar cells the 2° neurons, and ganglion cells the 3° neurons), and a horizontal arrangement (amacrine and horizontal cells in between those layers connecting neuronal impulses from neighboring cells for better contrast, etc.).

Each vertical tier of 2° and 3° neurons is addressed by a receptive field (= rods and cones) of differing size, depending on whether its a 2° or a 3° neuron, and how much horizontal relaying is fed to them in between tiers. Individual impulses from photoreceptor cells are bundled as one receptive field into a single impulse, but different receptive fields can partially overlap each other.

But this is where the fun just starts. The human eye has two separate systems of vision: Rods making up the parvocellular system for light/dark vision, and cones the magnocellular system for acute and color vision. Accordingly, each system is relayed into different parts of the brain: The parvocellular system is fed into the dorsal pathway, which connects with those parts of the brain that coordinate movement. Spatial orientation plays the pivotal role here.

The magnocellular system feeds in a ventral pathway into the limbic system, which is a repository of time- and space independent, content aware emotional memory. Pattern and situation recognition happens in the limbic system.

Now translate that into megapixels.......

Beatsy
Beatsy Contributing Member • Posts: 670
Re: Reasons for wanting higher mega pixel count

One of the best posts I've read anywhere! Fascinating! Off to Google more. Thanks.

 Beatsy's gear list:Beatsy's gear list
Sony a7R II Sony a9 Sony a7R IV Canon MP-E 65mm f/2.5 1-5x Macro Sony Carl Zeiss Planar T* 50mm F1.4 ZA SSM +13 more
Joachim Wulfers
Joachim Wulfers Veteran Member • Posts: 3,474
Re: Reasons for wanting higher mega pixel count

JimKasson wrote:

KE_DP wrote:

Considering Moore's Law photography data in gigapixels are only a matter of time - maybe even terapixels.

There are some considerable difficulties building a lens that can provide terapixels of information -- as opposed to noise -- in a single capture. The simplest one is diffraction.

Isn't diffraction already setting in at Apertures of 5.6 or 8 in a camera like the A7R4? If that is the case what happens with all the nice landscape optics where photographers shoot at F11 and over?

-- hide signature --
 Joachim Wulfers's gear list:Joachim Wulfers's gear list
Fujifilm X100T Sony a6000 Sony E 18-200mm F3.5-6.3 OSS Voigtlander 21mm F4 Color Skopar Pancake II Sony Carl Zeiss Sonnar T* E 24mm F1.8 ZA +10 more
JimKasson
JimKasson Forum Pro • Posts: 26,717
Managing blur
2

Joachim Wulfers wrote:

JimKasson wrote:

KE_DP wrote:

Considering Moore's Law photography data in gigapixels are only a matter of time - maybe even terapixels.

There are some considerable difficulties building a lens that can provide terapixels of information -- as opposed to noise -- in a single capture. The simplest one is diffraction.

Isn't diffraction already setting in at Apertures of 5.6 or 8 in a camera like the A7R4? If that is the case what happens with all the nice landscape optics where photographers shoot at F11 and over?

There is no aperture where diffraction suddenly appears. Landscape photography is partially about managing sources of blur. Defocus blur and diffraction blur should both be considered. Some DOF apps allow that. In addition, I think that sensor blur due to the finite pixel aperture should also be considered.

I've written a tool to optimize those three things, but it's not portable.

https://blog.kasson.com/the-last-word/choosing-f-stops-and-focus-distance-for-landscapes/

https://blog.kasson.com/the-last-word/optimizing-f-stops-and-focus-distance-for-landscapes/

https://blog.kasson.com/the-last-word/optimizing-aperture-and-focus-distance-an-example/

https://blog.kasson.com/the-last-word/optimizing-aperture-and-focus-distance-another-example/

https://blog.kasson.com/nikon-z6-7/ff-examples-of-optimal-blur-management/

Looking at these examples will give you a feel for what's involved. Often, the sharpest images are obtained with quite a bit of diffraction blur.

Jim

-- hide signature --
 JimKasson's gear list:JimKasson's gear list
Nikon D5 Sony a7 III Nikon Z7 Fujifilm GFX 100 Sony a7R IV +4 more
Joachim Wulfers
Joachim Wulfers Veteran Member • Posts: 3,474
Re: Managing blur

JimKasson wrote:

Joachim Wulfers wrote:

JimKasson wrote:

KE_DP wrote:

Considering Moore's Law photography data in gigapixels are only a matter of time - maybe even terapixels.

There are some considerable difficulties building a lens that can provide terapixels of information -- as opposed to noise -- in a single capture. The simplest one is diffraction.

Isn't diffraction already setting in at Apertures of 5.6 or 8 in a camera like the A7R4? If that is the case what happens with all the nice landscape optics where photographers shoot at F11 and over?

There is no aperture where diffraction suddenly appears. Landscape photography is partially about managing sources of blur. Defocus blur and diffraction blur should both be considered. Some DOF apps allow that. In addition, I think that sensor blur due to the finite pixel aperture should also be considered.

I've written a tool to optimize those three things, but it's not portable.

https://blog.kasson.com/the-last-word/choosing-f-stops-and-focus-distance-for-landscapes/

https://blog.kasson.com/the-last-word/optimizing-f-stops-and-focus-distance-for-landscapes/

https://blog.kasson.com/the-last-word/optimizing-aperture-and-focus-distance-an-example/

https://blog.kasson.com/the-last-word/optimizing-aperture-and-focus-distance-another-example/

https://blog.kasson.com/nikon-z6-7/ff-examples-of-optimal-blur-management/

Looking at these examples will give you a feel for what's involved. Often, the sharpest images are obtained with quite a bit of diffraction blur.

Jim

At the risk of sounding ignorant, which I am about this topic, what I meant is that the diffraction of a lens, even at 5.6 or 8 may cause part of the light captured to miss the pixels (when you visualize each pixel as a cup) once the pixels become extremely small. At 3.8 µm the pixels of an A7R4 are already becoming some of the smallest among all formats (smart phones not included). Perhaps that is what you call sensor blurr?

-- hide signature --
 Joachim Wulfers's gear list:Joachim Wulfers's gear list
Fujifilm X100T Sony a6000 Sony E 18-200mm F3.5-6.3 OSS Voigtlander 21mm F4 Color Skopar Pancake II Sony Carl Zeiss Sonnar T* E 24mm F1.8 ZA +10 more
JimKasson
JimKasson Forum Pro • Posts: 26,717
Re: Managing blur

Joachim Wulfers wrote:

JimKasson wrote:

Joachim Wulfers wrote:

JimKasson wrote:

KE_DP wrote:

Considering Moore's Law photography data in gigapixels are only a matter of time - maybe even terapixels.

There are some considerable difficulties building a lens that can provide terapixels of information -- as opposed to noise -- in a single capture. The simplest one is diffraction.

Isn't diffraction already setting in at Apertures of 5.6 or 8 in a camera like the A7R4? If that is the case what happens with all the nice landscape optics where photographers shoot at F11 and over?

There is no aperture where diffraction suddenly appears. Landscape photography is partially about managing sources of blur. Defocus blur and diffraction blur should both be considered. Some DOF apps allow that. In addition, I think that sensor blur due to the finite pixel aperture should also be considered.

I've written a tool to optimize those three things, but it's not portable.

https://blog.kasson.com/the-last-word/choosing-f-stops-and-focus-distance-for-landscapes/

https://blog.kasson.com/the-last-word/optimizing-f-stops-and-focus-distance-for-landscapes/

https://blog.kasson.com/the-last-word/optimizing-aperture-and-focus-distance-an-example/

https://blog.kasson.com/the-last-word/optimizing-aperture-and-focus-distance-another-example/

https://blog.kasson.com/nikon-z6-7/ff-examples-of-optimal-blur-management/

Looking at these examples will give you a feel for what's involved. Often, the sharpest images are obtained with quite a bit of diffraction blur.

At the risk of sounding ignorant, which I am about this topic, what I meant is that the diffraction of a lens, even at 5.6 or 8 may cause part of the light captured to miss the pixels (when you visualize each pixel as a cup) once the pixels become extremely small. At 3.8 µm the pixels of an A7R4 are already becoming some of the smallest among all formats (smart phones not included). Perhaps that is what you call sensor blurr?

I haven't tested the a7RIV, of course, but effective fill factor on the BSI FF Sony sensors has been close to 100% up to now.

The fill factor (1 - any portion of the pixel/microlens that is unresponsive to light) is part of the sensor blur, as is the AA filter, if present. Low fill factors produce sharper images, but are more prone to aliasing.

Jim

-- hide signature --
 JimKasson's gear list:JimKasson's gear list
Nikon D5 Sony a7 III Nikon Z7 Fujifilm GFX 100 Sony a7R IV +4 more
JimKasson
JimKasson Forum Pro • Posts: 26,717
Re: Managing blur
1

Joachim Wulfers wrote:

Perhaps that is what you call sensor blurr?

Here's an excellent discussion of that subject:

http://www.strollswithmydog.com/testing-sharpness-model/

Scroll down to "The Model’s Components".

Jim

-- hide signature --
 JimKasson's gear list:JimKasson's gear list
Nikon D5 Sony a7 III Nikon Z7 Fujifilm GFX 100 Sony a7R IV +4 more
sportyaccordy Forum Pro • Posts: 15,402
Re: Then 12MP is enough?

Steven Rodgers wrote:

I have a high end 4k monitor.

IIRC sony uses 6K and downsized to get the sharpest 4K video.

Take into account some aggressive cropping and 12MP or 16MP would be enough for your two points. A 12 MP sensor may have less noise due to the larger pixel size, and 6MP is enough for sharp 4K images. And I've seen highly detailed 30 inch prints from 8MP images, so that is covered too.

I think the real reason for more MP is the same reason we buy Dodge Demons. No one here will admit this I bet. I just bought an A7RIII and I drive a car with a large v8 so I am in that group.

According to people a lot smarter than me, when you factor in the losses from a Bayer filter the effective color resolution is about 1/2 the native resolution (with a bias towards greens). You also have to factor in aspect ratio. To view a full 3:2 photo you only get about 6 of the 8MP of your 4K monitor. So to that end 12MP is all that's "needed".

That said I have 6MP photos from my D40 that look great on my 4K monitor.

-- hide signature --

Sometimes I take pictures with my gear- https://www.flickr.com/photos/41601371@N00/

 sportyaccordy's gear list:sportyaccordy's gear list
NEX-5T Sony a7R II Canon EOS 5D Mark IV Sony FE 28mm F2 Samyang 135mm F2.0 +3 more
CE3 Contributing Member • Posts: 634
Re: Reasons for wanting higher mega pixel count
1

The main reason I like the higher mega pixels is for increased sharpness and future proofing. As display resolutions continue to increase, I want my images to be able to look sharp for as long as possible. That said, I'm sure someday we'll be using AI to upscale our 8MP smartphone shots so they look great on 8K displays,

Being able to crop more certainly comes in handy at times, but I rarely ever shoot with the intention of cropping no matter what camera I'm using. The goal is usually to crop as little as possible, or not at all.

 CE3's gear list:CE3's gear list
Sony a7R II Sony a6500 Voigtlander 40mm F1.4 Nokton Classic Sony E 50mm F1.8 OSS Sony E 55-210mm F4.5-6.3 OSS +10 more
Paul Barnard
Paul Barnard Veteran Member • Posts: 3,170
Re: Reasons for wanting higher mega pixel count

CE3 wrote:

The main reason I like the higher mega pixels is for increased sharpness and future proofing. As display resolutions continue to increase, I want my images to be able to look sharp for as long as possible. That said, I'm sure someday we'll be using AI to upscale our 8MP smartphone shots so they look great on 8K displays,

Being able to crop more certainly comes in handy at times, but I rarely ever shoot with the intention of cropping no matter what camera I'm using. The goal is usually to crop as little as possible, or not at all.

Some of us are already upscaling our old 4Mp images using AI. Topaz Gigapixel does a remarkably good job.

 Paul Barnard's gear list:Paul Barnard's gear list
Sony a7R III Sony FE 55mm F1.8 Sony FE 70-200 F4 Zeiss Batis 25mm F2 Sony 1.4x Teleconverter (2016) +4 more
DejayRezme Regular Member • Posts: 131
Re: Reasons for wanting higher mega pixel count

While the megapixels increase by 42% with the A7RIV, the horizontal size of the resolution only increased by 20%. And that is how I perceive resolution with images, there is always too little when zooming in because it's more about the size of the pixel, not the area. Or the radius of the pixel.

Details aren't captured by more area, it's captured by more subdivisions.

So you can look at that 61MP and say "oh only a modest perceived gain for a lot of memory and bandwidth requirements it's not worth it" or you can say "oh such a modest perceived gain we need even more megapixels!". But the numbers only look that great because they grow with the square of the "real resolution".

I'm also don't like the bayer filter. Obviously it works ok but imagine watching a desktop screen like that. These technical limitations have to determine what kind of scenes looks good and what scenes don't so they also have to limit creative freedom in a small way. So technically 40MP is just the minimum you need to produce a perfect image on a 4k screen, and 60MP is just a 20% increase to allow some modest cropping.

jpozinmiami Forum Member • Posts: 68
Re: Reasons for wanting higher mega pixel count

Hi there! I'm moving from the a6500 to the A7rii. Good move? Or should I try for the a7riii?  I ask since you've owned both. My plan was to get into the A7rii and build glass - then upgrade cameras later on.

Erik Kaffehr
Erik Kaffehr Senior Member • Posts: 3,219
Re: Reasons for wanting higher mega pixel count

JimKasson wrote:

xh43k wrote:

Resolution of an eye according to quick google search seems to be 324 megapixels.

That number is way too high considering that the fovea only subtends about one degree of visual field.

Or are you talking about a stitched image due to saccade?

I am a bit impressed by the exact number, especially with regard to the somewhat fuzzy subject.

That said, human vision in combination with the human brain is certainly a very impressive construct.

Best regards

Erik

-- hide signature --

Erik Kaffehr
Website: http://echophoto.dnsalias.net
Magic uses to disappear in controlled experiments…
Gallery: http://echophoto.smugmug.com
Articles: http://echophoto.dnsalias.net/ekr/index.php/photoarticles

(unknown member) Senior Member • Posts: 1,233
Re: Reasons for wanting higher mega pixel count

jpozinmiami wrote:

Hi there! I'm moving from the a6500 to the A7rii. Good move? Or should I try for the a7riii? I ask since you've owned both. My plan was to get into the A7rii and build glass - then upgrade cameras later on.

Similar thread: https://www.dpreview.com/forums/thread/4411622

SilvanBromide Senior Member • Posts: 3,948
Re: Reasons for wanting higher mega pixel count

jpozinmiami wrote:

Hi there! I'm moving from the a6500 to the A7rii. Good move? Or should I try for the a7riii? I ask since you've owned both. My plan was to get into the A7rii and build glass - then upgrade cameras later on.

In short, the a7Rii will be a good move in relation to image quality, but less so regarding AF, which is a little slower and less accurate.

If you can swing a move to the a7Rii the AF speed and accuracy will be closer to the a6500, plus you will have the larger Z battery and various other ergonomic improvements.

Conversely, since the a7Rii uses the same battery as the a6500 you may be able to use your existing battery/batteries with it, and despite having slightly less AF speed and accuracy it is still an excellent camera (and great value for its price these days!).

-- hide signature --

Former Canon, Nikon and Pentax user.
Online Gallery: https://500px.com/raycologon

 SilvanBromide's gear list:SilvanBromide's gear list
Sony a7R III Sony FE 35mm F1.4 Sony FE 85mm F1.4 GM Sony a6500 Sony FE 35mm F2.8 +25 more
Cudacke Dees Regular Member • Posts: 192
Re: Reasons for wanting higher mega pixel count
2

Jacques Cornell wrote:

Cudacke Dees wrote:

10 years ago people say 12MP is enough.
12MP which is 4272 x 2848 on Sony camera.

It is only slightly larger than my 8MP 4K resolution 15 inch HP spectre x360 laptop screen which I look at every day no farther than 2 foot.
I won't even be able to APS-C crop it and still get a full screen image.

with 24MP a APS-C crop barely larger.

so yea unless you are planning to die in 10 years.....

What's your point? Ten years later, a 12MP file is still sufficient to display full-screen without upscaling on a 4K display of any size or to make a print at least 12"x18". If your laptop 10 years from now has an 8K display, your eyes won't be able to discern the difference.

what do you mean?

I am already seeing the difference on my 15 inch 4K screen every day.

Do you have an 8K display and 61MP camera to see the difference from 4K can not be seen?

Do you?

that is my point.

so yea unless you are planning to die in 10 years.....

The technology is improving.
What people say enough 10 years ago already reaches it limits.

If you want to print bigger than this or view on a 5K or higher-rez display and view at abnormally close distances, then yes, it helps to have more than 12MP.

12 MP only barely bigger than my 15 inch 4K display with an APS-c crop it is smaller than my screen.  I can see the difference every day by just using it normally.
you don't need to make big prints... you just need a new computer too see it. or maybe a good eye doctor would help in your case if you really cannot tell.

But, now we're talking about exceeding 42MP, which is a very much higher threshold and one that 99% of photographers will never surpass.

oh well I am not 99% then (where is this # coming from???)

ActionPhotoPassion Senior Member • Posts: 1,517
Re: Reasons for wanting higher mega pixel count

CE3 wrote:

The main reason I like the higher mega pixels is for increased sharpness

Well a micro shake on the 42Mpx sensor is unforgiving for the result of an image where on the 24Mpx sensor you can still use the image.

So saying that sharpness increases with the Mpx is only dependant of the operator. Now if like md you're more often on a tripod than handheld of course you won't have any problem

 ActionPhotoPassion's gear list:ActionPhotoPassion's gear list
Konica Minolta Maxxum 7D Sony SLT-A58 Sony a77 II Sony a99 II Sony 500mm F8 Reflex +16 more
pollup Regular Member • Posts: 241
Re: Reasons for wanting higher mega pixel count
1

To me, 24mp is enough in my images and my computer is too slow to handle 61mp. However I'd like to have a 80+mp camera, why? Because this system will save me size, weight and money, as I'll be able to turn that high res camera with a prime lens into a 24mp camera multi prime system. So instead of carrying 3 primes, I carry only one, that's more convenient and cheaper. All we need is the ability for the camera to save small/medium raws, and not only full res raw. Ideally we should be able to specify a resolution, like 24mp, and then the camera will automatically select small/medium/full depending on the crop factor. (I mean, if I'm in crop mode, then maybe I don't want to make the raw even smaller).

 pollup's gear list:pollup's gear list
Canon EOS 550D Sony a7R II Sony a9 Canon EF-S 17-55mm f/2.8 IS USM Sony FE 35mm F2.8 +4 more
SilvanBromide Senior Member • Posts: 3,948
Re: Reasons for wanting higher mega pixel count

ActionPhotoPassion wrote:

CE3 wrote:

The main reason I like the higher mega pixels is for increased sharpness

Well a micro shake on the 42Mpx sensor is unforgiving for the result of an image where on the 24Mpx sensor you can still use the image.

Well, to be fair, if the image - micro shake and all - would still have been usable with a 24Mpx sensor, then downscaling the 42Mpx image to 24Mpx should give you an equivalent result.

It's only when you want to display or print (or crop etc) to reveal the finer detail of the high res image that tiny amounts of shake become a concern.

So saying that sharpness increases with the Mpx is only dependant of the operator. Now if like md you're more often on a tripod than handheld of course you won't have any problem

Agreed - assuming the tripod is stable and there is little wind etc. etc. (but that's a whole other discussion!). ; )

-- hide signature --

Former Canon, Nikon and Pentax user.
Online Gallery: https://500px.com/raycologon

 SilvanBromide's gear list:SilvanBromide's gear list
Sony a7R III Sony FE 35mm F1.4 Sony FE 85mm F1.4 GM Sony a6500 Sony FE 35mm F2.8 +25 more
Scottelly
Scottelly Forum Pro • Posts: 13,873
Re: Reasons for wanting higher mega pixel count
3

JimKasson wrote:

canonpfs wrote:

Much is said about the Sony A7R IV's "too high" mega pixel count. It seems the only reason that people can think of for needing a high mega pixel count is cropping. Besides cropping, here are two additional reasons for wanting more mega pixels:

1. Sharper images. Have you ever looked at an image on your rear LCD and thought that they were sharp only to find them blurry on your home monitor? Yes, I know we should look at our images on the LCD at higher magnifications but please bear with me for a moment. The reason why the blurry images looked sharp on the LCD is because a large image is displayed very small. So you shoot in low light and there is a breeze. You are already at a high ISO to get a higher shutter speed but the flowers in the foreground are still slightly out of focus. With lots of mega pixels available this image can be down sampled. At a smaller size the flowers are now sharp. Taking an image from 61MP down to say 18MP sharpens slightly out of focus areas.

That is true, but it's a second order effect if the CoC of the blurry flowers is much bigger than the pixel pitch. It occurs because the sharpening algorithms work better with more samples. By the time the CoC gets to 4 or 5 pixel pitches, the improvement is virtually gone.

2. Lower noise. Provided the 61MP sensor provides the same high ISO performance as the 42MP sensor the larger sensor will result in lower noise when down sampled. Noise just seems to magically disappear with down sampling. So if you have noise in the 61MP image just down sample it and the perceptible noise will be less.

This is true if you use nonlinear noise reduction. If you use linear noise reduction, it's pretty close to a wash, since the full well capacity for a given sensor technology is mainly proportional to the area of the pixel.

This is something I've been reading for years and years, yet the new 61 MP Sony sensor offers more dynamic range than a similar sized (full-frame) 42 MP Sony sensor. Since the technology is mature, and since both are back-lit sensors that have basically maxed out their possible fill-factor, shouldn't the 42 MP sensor offer more dynamic range, rather than less, if what you're saying is really true? This concept of photo-sites with larger area being better for dynamic range bothered me when the Nikon D7100 came out, offering more dynamic range than any previous full-frame camera from Nikon or Canon, despite the photo-sites having a much smaller surface area. Nobody was ever able to explain to me why the little, APS-C sensor could capture so much more dynamic range than the older full-frame sensors. Sure, they said there was newer technology in the Nikon D7100 sensor, but that only goes so far, when people continue to make claims like this one you've just made. Given the fact that technology continues to improve, I don't see how what you're saying can be applicable, yet people keep saying stuff like, "They can't get much more out of a sensor, because the limits of the laws of physics have nearly been reached." I've read comments like that for more than ten years, yet camera/sensor companies keep on making sensors that have smaller photo-sites, yet can somehow capture more dynamic range.

What are your thoughts on this Jim?

3. Higher usable ISO. For the same reason as mentioned above the higher mega pixel count allows you to use a higher ISO because the additional noise generated by the higher ISO will be cancelled out by down sampling the image (within reason of course).

Again, only true if you use nonlinear noise reduction.

So call me crazy if you please but I am very pleased with the higher mega pixel count. It has its uses other than just cropping.

It has advantages that you haven't mentioned: less false color, less aliasing, sharper images in general.

Jim

-- hide signature --

Scott Barton Kennelly
https://www.bigprintphotos.com/

 Scottelly's gear list:Scottelly's gear list
Sony SLT-A65 Sigma SD1 Merrill Nikon D810 Sigma sd Quattro H Sony DT 18-55mm F3.5-5.6 SAM +20 more
Keyboard shortcuts:
FForum MMy threads